Troubleshooting Severe Airflow Obstruction With a Pressure-Limited Transport Ventilator: Lessons From Two Cases

Area of Science:

• Critical Care Medicine
• Pulmonary Medicine
• Mechanical Ventilation

Background:

• Severe asthma and chronic obstructive pulmonary disease (COPD) exacerbations pose significant challenges for invasive mechanical ventilation.
• Optimal ventilation strategies involve low respiratory rates and high inspiratory flow to minimize dynamic hyperinflation and prolong expiratory time.
• Some intensive care unit (ICU) ventilators have limitations in peak inspiratory pressure capacity, potentially hindering optimal ventilation delivery.

Purpose of the Study:

• To describe two cases of severe airflow obstruction where the required ventilation strategy exceeded the peak pressure capacity of the Hamilton T1 transport ventilator.
• To present an alternative ventilation strategy to overcome ventilator pressure limitations in critically ill patients.
• To raise awareness among clinicians regarding potential ventilator pressure limitations and appropriate strategy adjustments.

Main Methods:

• Case report of two patients with severe airflow obstruction requiring invasive mechanical ventilation.
• Identification of peak inspiratory pressure limitations with the Hamilton T1 transport ventilator.
• Implementation of a modified ventilation strategy using pressure-regulated volume control, maximized driving pressure, and titrated inspiratory time.

Main Results:

• The standard ventilation strategy aiming for low respiratory rates and high inspiratory flow exceeded the Hamilton T1 ventilator's pressure capacity.
• A modified strategy involving pressure regulation, maximized driving pressure, and adjusted inspiratory time successfully managed ventilation despite the initial limitation.
• The adjusted strategy allowed for effective ventilation, preventing dynamic hyperinflation in patients with severe airflow obstruction.

Conclusions:

• Clinicians must be aware of potential peak pressure limitations in specific ICU ventilators, such as the Hamilton T1.
• Adjusting ventilation to pressure-regulated modes and optimizing parameters like driving pressure and inspiratory time can overcome ventilator capacity limits.
• Understanding and adapting ventilation strategies are crucial for managing patients with severe airflow obstruction and preventing complications during mechanical ventilation.